We are using the EFM8UB1 chip to implement the USB HID interface, then communicate with the SAM L11 via SPI. After considering many MCUs with USB interfaces, i

We are using the EFM8UB1 chip to implement the USB HID interface, then communicate with the SAM L11 via SPI. After considering many MCUs with USB interfaces, it seems to always be more cost effective to get the non-USB MCU and use the EFM8UB1 (from a BOM perspective anyways). The lesser chance of having a backdoor is a plus! Here's our schematic: https://i.imgur.com/sVQ34em.pnghttps://i.imgur.com/sVQ34em.png https://i.imgur.com/sVQ34em.pnghttps://i.imgur.com/sVQ34em.p... Still have to document this better on Github :)